This book constitutes the refereed proceedings of the 13th Conference on Advanced Computer Architecture, ACA 2020, held in Kunming, China, in August 2020. Due to the COVID-19 pandemic the conference was held online.The 24 revised full papers presented were carefully reviewed and selected from 105 submissions. The papers of this volume are organized in topical sections on: interconnection network, router and network interface architecture; accelerator-based, application-specific and...